Grant's next adventure with the Doctor was on his birthplace, the planetAgora, again in the year 2191. They found the Cybermen had been using the planet to gather strong males for cyber-conversion. Grant met his father, Ben Taggart, who was killed in an unsuccessful attempt to convert him into a Cyberman as Grant watched. This moved Grant to volunteer to become a Bronze Knight, one of a resistance group of Agorans who themselves used cybernetic implants to become stronger to defeat the Cybermen. He was convinced not to give up his humanity by the knights' creator, the scientist Maxine Carter. The Cybermen attacked the Bronze Knights and slaughtered them all, but Grant lowered their base's temperature and deactivated the Cybermen. (PROSE: Killing Ground)

Grant suffered from robophobia, a morbid fear of androids and robots. Through his travels with the Doctor he learned the roots of his condition; he had repressed memories of watching his mother being killed by Cybermen. (PROSE: Killing Ground)

Short stories featuring Grant appeared in the unlicenced charity publication Perfect Timing.

The story "Wish Upon a Star Beast" featured the Doctor and Grant encountering a group of killer Meeps in the Santaland amusement centre in Norway during the 22nd century.

The story "Schrödinger's Botanist" takes place over a longer span of time, during which Grant and the Doctor had many adventures and were joined on their travels by a Legion. The story concluded with Grant linking his mind to a computer infected by a virus and being seriously injured. Unwilling to risk Grant's life any further, the Doctor left him at the Bi-Al Foundation. The Doctor later regretted abandoning Grant and returned to apologise, but Grant did not forgive him and they parted on bitter terms.

The Sixth Doctor's companions from stage plays are difficult to assert with certainty, as different actors played the Doctor in the same play. If a medium is not mentioned, then this incarnation did not have companions who were original to that medium; it does not mean that this Doctor failed to appear in that medium.